And john charters



v March 10, 1925.

J. A. IMHOF ET AL PROCESS OF MAKING PRINTS Original Filed Oct. 31, 1922 1 VB TORS T N CL. m S E R DI A TT ORNE Y Patented Mar'. 10, 1925.

UNITED STATES PATENT OFFICE.

JOSEPH A. manor, NEW YORK. AND JOHN CHARTERS, OI ASTORIA, NEW YORK, AS- SIGNORS TO INVISIBLE OOIIOR PRINT CORPORATION, OF NEW YORK, N. Y., A COR- PORATION 01' NEW YORK.

PROCESS OF MAKING PRINTS.

Original application filed October 81, 1922, Serial N01 598,081. Divided and this application filed February 7, 1923.

To all whom it may concern:

Be it known that we, Josn'rn A. IMHOF, a citizen of the United States, and a resident of the city of New York, in the bor- 5 ough of Manhattan, county and State of New York. and JOHN CHARTERS, a citizen of the United States, and resident of Astoria, Long Island City, in the county of Queens and State of New York, have invented certain new and useful Improvements in Processes of Making Prints, of which the following is a specification.

'This invention relates to an im roved process of making prints and is a division of application Serial No. 598,081, filed Qctober 31,1922.

In'the prior art of making prints, hidden images have beenproduced in various ways and have been renderedvisible by the use of chemicals. The main object and feature of the present invention is to render the hidden object visible by the application of water without the use of specia chemicals.

In the accompanying drawings the invention is embodied in a preferred form in which- 'Figs. 1, 2, 3 and 4 are diagrammatic views showing the steps of the invention for producing ahidden image and-the revealing of the same.

other material capable of receiving impressions. In Fig. 2 this surface is shown as having received an impression of an invisible image 3 indicated for convenience by the word President in dotted'outline. This image is made preferably with .an. im ression of translucent varnish and is t erefore both insoluble in water and invisible and may be made either from asolid form or from a half-tone or the like such as a Ben Dav plate. If desired the varnish maygbe slightly tinted so as to match as nearly as possible the tone or color of surface 1 before printin The tint thus used may be a white oil i 2 indicates an overlying) impressionpim dicated for convenience y sect on l nes,

1 indicates a printing surface of paper or Serial No. 617,457.

which forms a visible image. This im ression 2 is made with ink consisting w 011 of or carrying latent coloring matter suc as aniline dye soluble in water as explained in Patent No. 1,384,663, dated July 12, 1921. It will be understood that a single color only need be used and that this color may be the same as the oily body carrying the color, if such be employed. And further that the printing may be solid as when pro duced from a printing surface of uniform height or the printing may be done from half-tone plates or the like such as Ben Day plates.

The visible image thus disguises the subjacent invisible image which latter, however, is caused to emerge when water is applied as shown in Fig. 4 by contrast of color. It will be understood that the invisible image rinted in varnish tends to prevent the sinkin in of the ink or coloring matter of the visible image and that consequently when water is applied the ink overlying the invisible image is washed off in whole or in part thereby setting up the color contrast necessary to reveal the invisible image.

We claim:

1. The method of disguising and of subsequently renderin apparent a design in a printed product w ich consists in imprinting, on a surface, a substantially invisible image formed by an impression insoluble in water, then imprinting upon said surface in super-imposed relation to the first impression, another and visible image formed by an impression containing matter soluble in water, and then applying water to said surface to dissolve the second im ression and to remove it from that part 0 the surface carrying the invisible image to thereby render the latter visible by contrast in color with the initiall visible image.

2. The metho of disguising and of subsequently rendering apparent a design in a printed product which consists in imprintmg, on a surface, a substantially invisible imageformed'- by an impression oftranslu cent varnish, then imprmting upon said surface in superimposed relation to the first impression, another and visible image in color with the initially visible image. formed by an impression containing matter Signed at New York city, in the borough 10 soluble in water, and then applying water of Manhattan, county and State of New '5 to said surface to dissolve the second im- York, this 29th day of Jan. 1923.

pression and to remove it from that part of osEPBE A. IMHOF. the surface carrying the invisible'image to JOHN GHARTERS.

thereby render the latter visible by contrast 

